Laundering method



Patented Apr. 23, 1935 UNITED STATES 1,998,919 PATENT. OFFICE assignors to H. Kohnstamm & Co. Inc., New York, N. Y., a corporation of New York No Drawing.

Application September 6, 1933,

Serial No. 688,356

'l Claims.

per cent of fatty acid, as oleic, after a washing I operation using three rinsings and a sour. Any

dirt or grease that has'been emulsified in the washing operation with soap is also carried down on to the fabric, making the same ofif-color to a corresponding extent.

We have discovered that by using certain protective colloids, this fatty acid precipitate can be largely or entirely prevented. Consequently there is considerable less depositing of fatty acid and dirt on the fabric in the souring bath. The color and odor are improved and the extent of the rinsing operations can be reduced.

Heretofore, one or two rinses usually follow the sour and merely serve to remove the excess sour. Various souring agents are known, and the souring material may comprise one or more of such agents. In contrast, under our invention an improved sour is employed which enables us to can-y oil the fatty acid as well duringthe rinsing.

For example, with the use of a sour carrying a small percentage of gelatine, the emulsion of the fatty acids has been protected to such an extent that only 0.775 per cent has been precipitated after one washing, under the other conditions which produced the deposit of 1.709 per cent rebaths and a final washing with hot water and soap to remove the dirt. They are then subjected to a bath containing a bleach, soap and usually an alkali; the principal purpose of which bath is to remove stains and to assist in getting soap out of the goods. They are then passed through successive rinses, in some of which a souring composition is added to neutralize any remaining alkali. One or two rinses follow the sour and when our sour is used the latter rinses carry oif the fatty acid caused by the decomposition of soap in the rinse water or in the goods by action of the 80111.

The souring composition is composed of 84 per cent of sodium silicofluoride and 15 per cent sodium acid fluoride, to which 1 per cent of gelatine is added. Of this modified sour about two ounces are used to ,a hundred (100) pounds of the fabric. The exact percentage of the gelatine, or other protector, may be varied considerably according to circumstances.

Various modifications of the specific processes and agents referred to can be made by those skilled in the art without departing from the invention as defined in the following claims.

What we claim is 1. In laundering by washing the fabric with soap and subsequently subjecting it to a souring bath, the improvement which consists in providing a protective colloid during the souring step which protects the emulsion of fatty acids caused by the action of the sour on soap left over from the washing operation and substantially prevents precipitation of such fatty acids onto the fabric.

2. The method of laundering which includes in combination the washing of the fabric with soap and the subsequent subjection of it to a souring bath which contains in addition to the water, a mixture of sodium silicofiuoride, sodium acid fluoride and a. small percentage of a protective colloid.

3. The-method of laundering-which includes in combination the washing of the fabric with soap and the subsequent subjection of it to a souring bath containing in addition to the water, a mixture comprising about 84% sodium silicofiuoride 15% sodium acid fluoride and 1% gelatine.

4. A souring composition for laundry work comprising a mixture of souring material and a protective colloid adapted to prevent precipitation onto the fabric of the fatty acid in emulsified fonn caused by the action of the sour on the soap left over from the washing operation.

5. A souring composition for laundry work consisting of a mixture containing a comparatively large percentage of souring material and a comparatively small percentage of a protective colloid adapted to substantially prevent precipitation on the fabric of any fatty acid in emulsified form left in the goods or the rinse water by decomposition of soap from the previous washing operations. 9 v

6. The souring composition of claim 5, containing sodium silicofluoride, sodium acid fluoride and a small percentage of a protective colloid.

7. The souring composition of claim 5, consisting of about 84 per cent of sodium silicofluoride, about 15 per cent of sodium acid fluoride and about 1 per cent of gelatin.

ROBERT. A. PHAIR. JOHN GEORGE LUKASH. 

